1. Field of the Invention
This invention pertains generally to the field of games and amusement devices, and more particularly to the field of accessories for pool tables.
2. Description of the Prior Art
The table games of pool, billiards, and similar games are played by "shooting" the cue ball with the cue stick and causing it to collide with another ball so as to drive the target ball to a certain location, such as the pocket at the edge of the table. In some shots an alternative objective is to cause the cue ball, after suffering its first collision, to be deflected toward a second target ball. In both types of shots, players often accomplish these objectives by causing either the cue ball or the target ball to rebound from a rail cushion in a certain direction. Such shots are known as bank shots. In these shots, the player attempts to adjust the angle of incidence of the ball on the cushion so that the angle of rebound will be in the desired direction. If the ball collides elastically with the rail cushion, these angles will be equal. The player will therefore select the location on the rail such that the angle of rebound will be in the direction of the desired target, such as the table pocket. In order to achieve skill at the game, a player must develop the ability to accurately judge these angles.
Certain devices have been constructed in the past to aid in the development of this skill. One such device is disclosed in U.S. Pat. No. 3,463,593 (Horan) which describes a cue ball angle computer having a curved mirror to indicate the proper impact point for making accurate bank shots. This device is sometimes helpful in making bank shots in which the cue ball rebounds from the rail cushion. The device is used by moving it along the selected rail cushion and viewing the reflections of the cue ball and the target ball in the curved mirror. The position of this device is adjusted until these reflections appear at certain locations in the mirror, and the device indicates the necessary impact point on the rail cushion. Having located this impact point, the device is removed and the player shoots the cue ball toward this impact point.
The Horan device suffers from a serious drawback, in that the player must walk around the table and determine the point of impact, and then return back to the shooting position and make the shot. After having determined the impact point he must remember its precise location while returning to the shooting position, since the impact point is unmarked. This will generally introduce sufficient error in bank shots to cause the player to miss the shot, thus obviating the usefulness of the device. When a bank shot is made with the target ball striking the rail cushion, this error becomes much more important because it is the target ball which must be directed toward the impact point, rather than the cue ball. For this reason, the Horan device is substantially less useful in making target ball bank shots. Further, this device is rather complex and time-consuming to use, and it is of limited value in developing skill in making bank shots without the aid of the device. The player uses the device to measure the proper impact point, and then removes the device from the table and walks around to the shooting position. Thus, the device does not train the player to judge the impact point viewed from the shooting position.
To overcome these drawbacks, what is needed is a device that allows the player to "see" the shot directly at the time when he is preparing to shoot and to continue to "see" it during the entire shooting process. This would allow the player to view from the shooting position the entire geometry of the shot both before and after the collisions. A device which approaches these criteria is disclosed in U.S. Pat. No. 1,297,815 (Englehart), which teaches a pool table with mirrors or reflectors located under the rail cushion between the pockets to aid in making these bank shots. This device utilizes the optical principal of equality of the angles of incidence and reflection of rays of light. In making a bank shot, the player can view the target pocket and the target ball through the mirror, and judge the angle of the shot by lining up these reflections. The pocket and balls can be kept in view throughout the execution of the shot, so that the player does not have to remember the location of the impact point on the rail cushion. The device provides advantages over the invention of Horan in assisting a player to develop skill in judging these shots. However, this device suffers from the disadvantage that the mirrors are fixed in their angular position relative to the table and, being narrow mirrors, give the player a view of the pocket and target ball from a very narrow angular range of vision. This creates a problem in that different pool shots are necessarily made with different body positions or stances, and with varying angles at which the cue stick is held, and therefore the eyes of the player are at different heights above the table during the shot. Furthermore pool players vary in height and assume various postures while shooting, so that the player eye level above the table will vary considerably. Thus with the Englehart device only a very narrow range of bank shots can be seen by a given player. The balls will seldom be in such a position to afford the necessary view at the time of striking the cue ball without forcing the player to assume an unnatural sighting position to use this device. In short, for most bank shots a player will find this device difficult to use to line up the cue ball with the target ball and target pocket reflections in the mirror.
Accordingly, it is desirable to provide rail cushion mirrors which are movable, and which are adjustable in their orientation, so that they may be used with any bank shot regardless of the location of the cue ball, target ball, and target pocket, and regardless of the height or posture of the player and the height of the player's eyes above the table. Further, it is desirable to provide rail cushion mirrors for which these adjustments can be made by the player without moving from the location in which the shot is to be made. In addition, it is desirable to provide a rail cushion mirror which can be used and adapted on any pool table or billiard table, and which is portable and inexpensive to manufacture. It is further desirable to provide a rail cushion mirror which is decorative, and which has educational value in that it assists a player to learn to make accurate bank shots.